The Leskeaceae contain about 17 genera (Buck & Crum, 1990), and nearly 150 species primarily distributed in the temperate regions, extending into the montane tropics; seven genera and about 13 species in the Neotropics. A member of the order Hypnales, the family appears to be polythetic, lacking defining (unique) characters, and is characterized by trends, e.g., rather simple paraphyllia, laminal cells mostly short, often mammillose or papillose, and varying degrees in the reduction of the peristome.

Study Guide. Stems should be with some leaves removed to observe whether paraphyllia are absent or present, and if so whether they are simple or branched, and smooth or papillose. Sporophytes are useful to determine if the capsules are erect or curved, and the ornamentation of the outer exostome surface.